Will The Next Generation iPhone Look As Good As This Mockup?

Over the last few days there has been plenty of talk regarding the next generation iPad, but there seem to be only whispers about the next generation iPhone. As far as the design of the next iPhone, we don't have much more than leaked "iPhone 5" cases that appeared online prior to the iPhone 4S launch. While the leaked iPhone 5 cases seem to resemble the iPad 2, some people have a much different idea of what the next generation iPhone could look like.
Designer Antonio De Rosa has created this beautiful "iPhone SJ" mockup, which he states is "inspired by Steve Jobs."

I think this is a gorgeous vision of what the next iPhone could look like, but it seems unlikely to me. If Apple's launch-redesign-upgrade-redesign-upgrade way of dishing out iDevices has taught us anything, it's pretty much a given that the next iPhone will feature a new quad-core processor (A6?) and if we're lucky, a 10 megapixel camera. The polycarbonate back in De Rosa's design just looks too similar to the current iPhone models to be considered a redesign, in my opinion. Departing from the glass back of the iPhone 4/4S would be a necessary change to be considered "new" (think: iPhone 3GS to iPhone 4) and would give the iPhone a look like that of the iPad 2. Other than that, there isn't much to fuel the fire of speculation.
What do you think of this design? Would you like the next iPhone to be even thinner than the iPhone 4S? Do you think glass or metal would be better for the back? Be sure to let us know in the comments!